The image of a sexy black angel advertising a liquorice-flavoured nicotine chewing gum has prompted an apology from the ad agency responsible for the campaign.

Euro RSCG Life, the agency behind the offending Nicotinell chewing gum posters, said they had been printed in "error", in a move not authorised by the brand-owner, Novartis Consumer Health UK.

Novartis has issued a hasty recall of some of its Nicotinell posters and Euro RSCG Life said it apologised for this "regrettable incident".

The posters feature three pouting angels dressed in strappy frocks, high heels, and fluffy wings overpowering a devil, who represents nicotine cravings.

Each of the models represents a different Nicotinell flavour - mint, fruit and liquorice - and the posters carry the strapline, "You can beat cravings."

In posters spotted by a MediaGuardian.co.uk reader at Westminster and Waterloo tube stations in London, the black angel is clearly promoting the liquorice-flavoured gum, wearing a purple dress that matches the flavour.

But on other posters the black angel's dress is red, matching the fruit flavour, while the fiery redhead angel wears a purple dress.

Patrick Brindle, the managing director of Euro RSCG Life, said the agency experimented with a number of creative images and the wrong ones were displayed.

"Unfortunately it now seems that some of the experimental versions were retained by the printers and printed by them in error. They were then displayed by mistake without the knowledge and authority of Novartis Consumer Health UK," he added.

"Certain poster adverts that are now showing at specific locations at a number of London Underground stations were not authorised for publication.

"The mistake was drawn to the attention of Novartis Consumer Health UK which has taken immediate steps to remove all incorrect posters as soon as reasonably practicable. We apologise for this regrettable incident."

One of the posters was still visible on the platform at Bethnal Green underground station on Monday.

Emma Pierre-Joseph, a spokeswoman for Ligali, an African-British media monitoring group, said the posters were offensive.

"In our opinion it is more than a coincidence that the African model was aligned with the liquorice product," she said.

"The specific positioning of the African model in the advert is deliberately used to malign certain physical characteristics associated with her racial identity. The attempt at parodying an African woman as the 'black liquorice girl' is clearly offensive and we are quite frankly surprised that Nicotinell have taken this approach."

She added that representations of African people in advertisements over the decades had improved only slightly.

"With adverts like the current Ariel ad featuring a young boy in his 'uncomfortable' grass attire who races home to put on his 'nice' smooth western clothing, there is clearly still much room for improvement," she said.

Ms Pierre-Joseph also criticised the 2003 Land Rover advertisement, featuring members of the Kenyan Masai tribe forming the shape of a Land Rover, which she said along with the slogan "See it in the flesh" conjured up images of enslaved Africans being paraded and sold.